DevTools: Add support for installing node and running eslint over devtools.

third_party/WebKit/Source/devtools/scripts/local_node/node.py

 #!/usr/bin/env python
 # Copyright (c) 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 import shutil
 import sys
 import subprocess
 import tarfile
 import tempfile
 import urllib2
 
 THIS_DIR = os.path.dirname(os.path.abspath(__file__))
 
 DEFAULT_VERSION = '4.5.0'
 BUCKET = 'chromium-nodejs'
-
+RUNNING_AS_HOOK_FLAG = '--running-as-hook'
 
 def install_latest_node_js(version, tmp_dir):
     target_dir = os.path.join(THIS_DIR, 'runtimes', version)
     version_file = os.path.join(target_dir, 'VERSION')
 
     if sys.platform == 'win32':
         bin_location = os.path.join(target_dir, 'node.exe')
     else:
         bin_location = os.path.join(target_dir, 'bin', 'node')
 
@@ skipping 64 matching lines @@
             write_version = False
 
     if write_version:
         with open(version_file, 'w') as f:
             f.write(version)
 
     return bin_location
 
 
 def main(mode=None):
+    # Exit early if this is being invoked from `gclient runhooks`
+    # and INSTALL_NODE_FOR_DEVTOOLS=1 isn't present in the environment.
+    if (RUNNING_AS_HOOK_FLAG in sys.argv[1:] and
+            os.environ.get('INSTALL_NODE_FOR_DEVTOOLS', '0') != '1'):
+        return 0
+

[Dirk Pranke, 2016/11/11 02:11:20]

I'd rewrite this section to use argparse, e.g.:

    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('--running-as-hook', action='store_true')
    args, rest_args = parser.parse_known_args()
    if args.running_as_hooks and ...:

and then git rid of line 121 and pass rest_args on line 122 instead. Maybe a
line or two more of code, but a little bit more idiomatic python.

[chenwilliam, 2016/12/06 18:22:09]

Done.

     version = os.environ.get('NODE_VERSION', DEFAULT_VERSION)
     try:
         tmp_dir = tempfile.mkdtemp(dir=THIS_DIR)
         bin_location = install_latest_node_js(version, tmp_dir)
     finally:
         if os.path.exists(tmp_dir):
             shutil.rmtree(tmp_dir)
 
     if mode == 'npm':
         # TODO(hinoka): How about Windows...?
         bin_location = os.path.join(os.path.dirname(bin_location), 'npm')
 
-    return subprocess.call([bin_location, ] + sys.argv[1:])
+    node_args = [arg for arg in sys.argv[1:] if arg != RUNNING_AS_HOOK_FLAG]
+    return subprocess.call([bin_location, ] + node_args)
 
 
 if __name__ == '__main__':
     sys.exit(main())